Processes for the preparation of alpha-beta unsaturated cyclopolymethylenic ketones



Patented Oct. 20, 1953 1 OFFlCE-Y PROCESSES FOR THE PREPARATION OF a-flUN SATURATED CYCLOPOLYMETHYLENIC KETONES Max Stoll, Geneva, Switzerland,assignor to Firmenich & 00., successeurs de la Societe Anonyme M. Naef &Cie., Geneva, Switzerland, a. corporation'of Switzerland No Drawing.Application September 27, 1948,

Serial No. 51,482. 1947 3 Claims.

In Switzerland October 7,

The present invention has for subject matter a process for thepreparation of (1-5 unsaturated cyclopolymethylenic ketones, alkylatedor not, having from to 18 carbon atoms in the rin the formula of whichis FT L-CH=CH wherein R represents a chain of from '7 to groups CH2-=,one or more of which may be alkylated, for instance methylated. Y

That process consists in subjecting to a dehydration a1,2-cyclopolymethylenic ketol, alkylated or not, having in its ring anumber of members identical to that of the desired ketone.

The invention is based on the unexpected fact that in the1,2-cyclopolymethylene-ketols; the hydroxyl group is so slightly fixedto the molecule that it can easily be eliminated .by dehydrationaccording to known methods notwithstanding the instability whichcharacterizes those substances (self-oxidation, tautomerism).

Up to this date, the a-fi unsaturated polymethy'lenic ketones wereprepared by bromizing of the cyclopolymethylenic ketones, followed by anelimination of the hydrobromic acid- The cyclanones being, as it isexpensive substances, the

cyclenones so prepared could not in practice be utilized by reason oftheir excessive cost. Today, the 1,2-cyclopolymethylenic ketols arreadily accessible, owing to the process described in the U. S. A.patent application No. 714,650, filed December 6, 1946. Thus thedehydration of those substances constitutesa process for the preparationof a-p unsaturated cyclopolymethylenic ketones which is very economicaland representsa real industrial progress.

The dehydration may be carried out according to known methods with allthe cyclic compounds having from 10 to 18 members in the ring, thealkylated cyclanones included, or containing additional functionalgroups.

Instead of utilizing the 1,2-cyclanolones once purified, crudecyclanolones, such as those obtained by the process described in the U.S. A. patent application No. 714,650, may alsobe used as startingmaterial.

The yields exceed 80% of the theoretical yield,

as soon as the best working conditions are realized. The latteressentially consist in operating in the absence of oxygen, under goodvacuo, in dilution, etc.

The dehydration may also be carried out by converting the cyclanolonesinto esters of formula onooo-1v wherein R is an organic radical and a: anumber running from 8 to 16, then by subjecting said esters to a thermaldecomposition.

The 11-13 unsaturated cyclopolymethylenic ketones, alkylated or not,which have from 15 to 17 members in the ring have strong musk smells.

They constitute important raw, material forthe perfume industry, eitheras such or after catalytical reduction into saturated ketones. They mayalso be used for new chemical syntheses, such as for instance that ofthe racemic muscon,

which is another important raw" material for perfumery.

Below are given a'few examples of practice realization of the processaccording to the invention.

Eramplei '50. gr. of raw thapsoin of M. -Pl 40-431 prepared according toU. S. AQpatent application No. 714,650 with a 98.3% yield ofthe-theoretical yield, are introduced in a distilling flask which isdirectly connected with an upright tube 30 cm. long and 25 cm. wide,filled with catalyst. The flask is provided with three small side. tubesto take in the thermometer, the capillary tube and a piping connectedtoa manometer. Each one of those tubulures is surrounded by a tube withan in and out fiow of gas and filled with purified nitrogen, so as toexclude any trace of air let-in through leaks in the corks. ;The flaskand the catalyst tube may be electrically heated, and the temperatureadjustable to 1 C. In the centre of the catalyst is the quicksilverbulbof a longstemmed thermometer. The outletofthe catalyst tube isconnected to a receiving flask, the latter connected to two Dewar tubescooled at and serving as a pit to withhold water. Between these tubesand the receiving flask is a manometer to measure the vacuo at theoutlet of the catalyst tube. The entire equipment is evacuated with aC'enco pump at 0.08 mm. of Hg pressure. Kahlbaum aluminium oxide powdercarried by purified asbestos; it is heated to 350-352" C. Thetemperature of the distilling flask is first carried to 173 C., thengradually, within the space of 3 hours to 211 and finally within 1 hoursto 262. It is to be noted that, simultaneously, the vacuo in the flasklowers from 0.08 mm. to 2 and even 3 mm., while on the side of the Thecatalyst consists'of a Schering pump it remains at 0.08 mm. At the endof the thereafter diluted with ether and washed with operatiomit issetagain to 0.1 mm. sodium bicarbonate. Thus, 2.5 g. of cyclopenta- InthBH'ECGiViHgfiflSk CODdEIISB=374igfi0f .proddecenone tare obtained;"Through catalytical reuct which crystallizesifor the most part. In theduction this compound imay be converted into Dewar tubes condense 3.45g. of water and 1.8 g. 5 cyclopentadecanone, the semi-carbazone of ofxylene (resulting from the preparation of the 'which melts at 183-184.Yield: roughly 50% thapsoin). p ;"-f the-itheereticalryield.

On fractional disti11ation,; "-3;2tgr oftcyclohexajEmmpze decenone areseparated ofi which distil under 0.1 7 mm. between 128-130, and 3.5 g.are also sepa- 5 0f yq10p d ano1one-1,2 are heated rated ofi whichdistil btwe'en"if39l138 'The in'iva'cno with o ill g. ofnaphthalene-.fl-sulfonic physical constants of the first fraction are:aid- 0f the Oil bath, the 2s 0 93 1LD18=1 489, ter'i'e'sultmgffromthedehydration distils. After A oatalytical reduction in the presenceof'P'd fi 'f e 'iihydl'ated p O ufit is S j cted to on B8504 convertsthe cynldheiafdecenoneiinto 1a w n w hiia a a d the yc opntacyclohexadecanone, the semfcaibamne fif'Wliich dne fl is t r aft r dstil ed i a d melts at 180182 C. vaouo B. P. 0.1 mm; Hg:110-ll5. Yield:rough- The yield in pure product, determinedtb tt he 1y 1 0%-of=thetheoretical yield. catalytical reduction, is 72% of the theoretical WhatI claim is:

.yield. .If it is estimated 'thatthe crude thapsoin A p c s for t prparat n f a p -b contained *aiiout8'5% of'purethapsoinfthe yieldunsaturated'fcyclopolymethylenic ketones "having of the dehydrationreadlies'84f5%. I0 f'to 18"carb'0n atoms in "the ring consistin Example?in dehydrating a 10 th 1:8 ring"carbonatom 12 pcyclopolymethylenic"ketol 'by "passing vapors fo'f 6.6 g. of15-metliylcy6lopentadecanol-2-one-l said ketol under reducedpre'ssure*over-as'oliii 'fare distilled 'slowly' in asmall-cclumn-'cn"-aluinicontact mass comprising aluminum oxide.

"-"iflum= oxiii'eheated *to 325-310". 597'-g."of-di's- 2. A processfor'the preparation of alpha-beta tillate arecollectedfithlatterdieingrefractionunsaturated cyclopolymethylenicketones having "ated. l I6 g.- distil"antler- 05M mmkbetween120- 10 to18 carbon atoms dnthe ring consisting in 13?. The physical-constantsof'the"15 methyldehydrating a compound consisting of 10 to 18 ha -5124924.Yield: 74% =df the theoretical by passing vapors of said ktol underreduced pressure over a solid "contactnia'ss comprising 7 I'E-c'm'z'zple .3 aluminum oxide-suspendedon acariier.

l 3. The-method as defined in claim'l, wherein 2i;93333323333 ;gfifijgiggg jgi "the"'ketol vapors are mixed with i911 i'nert igas. ple 1. 25 gr.of crude cyblddecenoneare-obtained. .By a-treatment-withcalcium-chloride in benzene solution, 5 .0 g. of non-.dehydratedeprodnotare eliminated. 19 gr. of cyclodecenone-lare 'MAx-sToEL.

40 Rfere'n'ces 5 Cited in thefile Jof 'zthis Zpatent left. Tocharacterizezthetlatter, it is catalytically UNITED "STATES TATENTSreduced and l9.0 g of crude cyclodecanone are :Number Name L Dateobtained which 'f'yiel'd '19.- 5 of semicarbazone 2,139,360 Fairbai t l,t 1 ,1038 meltingalt Elli-200; Yield:'-roughly65,i% of 'the --2;-228,268:Hansley e Jan. l /Ll-JIQH *tlfecreti'calyield. -'2,-357;260 Joyce -Aug.29, .1944

Example 4 "UTHER REFERENCES f gr. fcyclopentadecanolorie liz distilled'Bilsteins 'ffHandbuch dr Or nisheh once are afdded 'to 20-"gr.-"o'f'1auric'=acid and-the t ihemie, vol. V111,;page '2 (1925)';\fo1.VIII,Tirst fn'ixture ls' heate'd inwacuo with fi g'rfiof' lauryl-Supplement, pages"504,505, 508 1931) vol.UII I, 'riloi'ide. Bothilauricacid an'd th'e *exces's Second Supplement, pages 5 6 and 10(1948). {of"chloride iare thereafter distilld 5 in ?a good .iPublishedinBe'rlm. vvacuo. When the ester obtained is'-decomposed :Locquin et al.: 'Bull.Soc. Chim., vol.'.45,jpages h rmin the tmpcrature df the= bath fr0m,'.11.07- .1.112 -192'9). v 250 "to 300'; meanwhile the yacup lowers "toCol0nge: Bun. Soc. .-Chim., Series 5, vol. 52, -2'0 I-5 m m. pages 57-6311935).

*"A product distils bet'ween 210? it is Taylor Richters OrganicChemistry;,.. "rfrationated. The 'fractionwhih di'stils bepages "77-'80and 107-109, Br'd' edition (1939). "tween-10512'5 under apressurehf 021mm. is .Nordemanlublishing 00.,'NewTYork.

1. A PROCESS FOR THE PREPARATION OF ALPHA-BETA UNSATURATEDCYCLOPOLYMETHYLENIC KETONES HAVING 10 TO 18 CARBON ATOMS IN THE RINGCONSISTING IN DEHYDRAFTING A 10 TO 18 RING CARBON ATOM1,2CYCLOPOLYMETHYLENIC KETOL BY PASSING VAPORS OF SAID KETOL UNDERREDUCED PRESSURE OVER A SOLID CONTACT MASS COMPRISING ALUMINUM OXIDE.